Cloning and expression analysis of kenaf (Hibiscus cannabinus L.) major lignin and cellulose biosynthesis gene sequences and polymer quantification during plant development     

Pasquale Chiaiese  Gianluca Ruotolo  Antonio Di MatteoAmalia De Santo Virzo  Anna De MarcoEdgardo Filippone 《Industrial Crops and Products》2011,34(1):1072-1078

In order to apply state-of-the-art molecular breeding techniques in fibre crop it is necessary to have a good knowledge of major polymer biosynthesis gene sequences and their expression pattern. Polymerase chain reaction was employed to isolate sequences of the major genes for lignin and cellulose biosynthesis in a kenaf cultivar. CeSA, 4cl, c4h, cad, and ccr gene primers were designed according to their conservative regions; partial sequences of lignin and cellulose biosynthesis genes were obtained. One actin II gene sequence was also isolated from the kenaf genome as a housekeeping gene to be employed in qPCR analysis. Expression levels of genes c4h, cad and CeSA in bark and core from plants harvested at three different growth stages were evaluated. Using qPCR analyses it was found that the expression levels of the two biosynthesis lignin genes in bark tissues increased during plant growth, while a negative trend was recorded in core tissues. In both bark and core, the quantity of lignin was positively correlated to plant growth while cellulose content decreased.  相似文献   

Improving the use of kenaf for kraft pulping by using mixtures of bast and core fibers     

J.C. Villar  E. Revilla  N. Gómez  J.M. Carbajo  J.L. Simón 《Industrial Crops and Products》2009,29(2-3):301-307

Kenaf (Hibiscus cannabinus L.) is a herbaceous annual plant amenable to use as a papermaking raw material. Kraft and soda pulping of kenaf have so far been done exclusively on the bark fraction (about 34–38% of the stem) or whole stem of the plant. Using kenaf bark exploits the higher quality of its bast fibers but reduces the typically high crop yields of this plant. In any case, core kraft pulp has acceptable properties some of which (e.g. tensile index, burst index) can even surpass those of bark pulp. Pulp made from both fractions has been found to exhibit better bonding properties than bark pulp. However, too high a proportion of core fibers can result in difficult drainage, a low tear strength or poor air permeability. These problems restrict the proportion of core that can be mixed with bast fibers, hinders separation of the two fractions and raises operational costs.The primary purpose of this study was to examine the influence of the core–bark ratio on the properties of mixed kenaf pulp. We used unrefined core pulp and refined bark pulp. Based on the results for kraft sacks, obtaining kenaf paper from both fractions has some advantages. Because Gurley air porosity changed dramatically with the proportion of core pulp used, it was used to determine the maximum amount of core fibers to be added to bast fibers. A proportion of up to 34% was found to have no adverse effect on air permeability. Such a proportion allowed paper strength to be preserved with an acceptable tear index (19.8 mN m²/g) and excellent tensile index (72 N m/g). Also, energy consumption was reduced if only the bark fraction was refined. The proposed strategy thus provides increased fiber yields of kenaf per hectare per year and valorizes the core fraction.  相似文献   

Relations between summer crops and ground cover legumes in a subtropical environment 3. Soil water use under sorghum and sunflower     

《Field Crops Research》1987,16(2):177-191

Vigna trilobata (L.) Verdc. and Medicago scutellata L. are short herbaceous legumes that help to reduce soil erosion when grown in association with row crops in the sub-humid/semi-arid subtropics. Soil water use and root distribution beneath sorghum (Sorghum bicolor (L.) Moench) and sunflower (Helianthus annuus L.) with and without V. trilobata were measured on a vertisol in South East Queensland. Sorghum was sown in October and January at densities of 10 and 5 plants m⁻² and sunflower at densities of 5 and 2.5 plants m⁻². V. trilobata seed was broadcast at 150 seeds m⁻². Pure stands of V. trilobata and M. scutellata were also sown.Soil profiles were uniformly wet to at least 2 m depth at each sowing date and remained so for the first 40 days of each growth cycle. Thereafter profiles dried rapidly over the next 40 days, providing opportunities for assessing soil water use. Subsequent rain restored and sustained profile water content until crop maturity.Undersown V. trilobata hastened soil drying, resulting in the extraction of 21 mm more water by maturity of the October sown crops. In pure stands, V. trilobata extracted water at the same rate as sunflower from the top 1.0 m of the soil profile, but not from the deeper layers. However, pure stands of M. scutellata extracted much less soil water than V. trilobata, with negligible extraction from below 0.8 m. Sunflower extracted 48 mm more water than sorghum in the January sowing because it had more roots and extracted more water from below 1.4 m.The capacity of V. trilobata to grow deep roots allows it to compete strongly for soil water and decrease yield of the main crop. Thus, a shallow-rooting plant would be preferred as a ground cover.  相似文献   

Reproductive partitioning and seed set efficiency in soybean,sunflower and maize     

《Field Crops Research》2001,72(3):163-175

Seed number per plant (SNP) can be modelled as a function of plant growth rate during the critical period for seed set (PGR_C), the proportion of plant growth partitioned to reproductive organs (P_R) and the minimum assimilate requirement per seed (λ). In comparison to PGR_C, less attention has been given to P_R and λ. In this paper, we analysed reproductive partitioning and λ in three species of contrasting reproductive strategies, soybean (Glycine max L. Merrill), sunflower (Helianthus annuus L.) and maize (Zea mays L.). To study plant-to-plant variation and to characterise stability of the variables analysed, we focused on individual plants grown under a wide range of plant densities. In soybean and sunflower, reproductive partitioning comprised about 50% of shoot growth, was fairly stable in a wide range of plant growth, and only decreased in a few, very small plants. In comparison, reproductive partitioning in non-prolific maize showed an optimum, was generally below 50% and exhibited a strong variation and instability at plant growth rates ≅2 g/day. Among species, stability of reproductive partitioning correlated inversely with a PGR_C threshold for reproductive growth and positively with reproductive plasticity at high PGR_C. Consideration of reproductive partitioning improved estimation of seed number, particularly in maize, a species prone to barrenness. Seed number as a function of reproductive growth was adequately described through linear (soybean) and hyperbolic models with x-intercepts (sunflower and maize). Seed set efficiency in terms of seed number per unit of reproductive growth (Ef) was constant only in soybean. In sunflower and maize, Ef increased with decreasing reproductive growth and became highly variable and unstable when reproductive growth was close to the threshold for seed set. In maize, such threshold was higher than in soybean and sunflower possibly as a consequence of a higher minimum combined demand for assimilate, resulting from a higher λ and number of simultaneously developing sinks. Inclusion of parameters assessing (i) stability in reproductive partitioning at low plant growth rates, and (ii) the minimum assimilate requirement per seed might improve seed number estimation.  相似文献   

Multiple buds are an alternative target to genetic manipulation of kenaf (Hibiscus cannabinus L.)     

Gianluca RuotoloArmando Del Toro  Pasquale Chiaiese  Edgardo Filippone 《Industrial Crops and Products》2011,34(1):937-942

Kenaf (Hibiscus cannabinus L.) is an annual fiber crop cultivated as an important source of cellulose and lignin. In the recent years, fibers have increased their economic importance as organic component in bio-composite materials. However, industry requires rheological improvements of these fibers. Genetic manipulation has been considered a feasible approach for fiber improvement; however, kenaf is considered a crop species difficult to manipulate. Here we propose meristematic cells from mature embryos as target for genetic modification driven by Agrobacterium tumefaciens. In vitro meristems proliferation and multiple shoots regeneration were evaluated by sowing kenaf mature seeds on medium containing three different concentration of thidiazuron, a substituted urea compound. The highest number of regenerated shoots was obtained from mature seeds germinated in presence of 10 μM thidiazuron after 14 days of culture. Interactions between two A. tumefaciens strains and two kenaf varieties were assessed. Transgene stable integration and its inheritance in T₁ generation were also verified, demonstrating that kenaf meristematic cells are an useful target for genetic manipulation by agroinfection.  相似文献   

Emergence date mediation of rice yield responses to equidistant spacing     

《Field Crops Research》1995,41(3):167-171

The objectives of this study were to assess the importance and interrelationships of emergence date and equidistant spacing to rice (Oryza sativa L.) plant and crop yields and yield variation. Field experiments were conducted in microplots at Keiser, Arkansas, in 1988 and 1989. The treatments were equidistant spacings of 40, 50, 60, and 80 mm. Emergence dates were recorded for plants in the center of each plot. Individual plant grain yields (Y_G) were recorded at maturity. Relative emergence times (t_R, differences in days) were computed between neighboring plants (t_RN and between each plant and the first-emerging plant in the plot (t_RC). Both expressions of t_R revealed that later-emerging plants yielded less than earlier-emerging plants. The negative effect of later emergence was more pronounced at the closer spacings and for t_RC than t_RN. Thus, t_RC was more meaningful than t_RN as expression of emergence time. At close spacings, increased t_RC decreased to a few days the length of time over which plants could emerge and still produce grain i.e., only the earlier emerging plants were productive. The results also indicated that more uniform crop maturity might result from increasing plant density.  相似文献   

红麻亲本与杂交组合产量、品质性状的遗传效应分析   总被引：8，自引：0，他引：8  

陈幼玉林荔辉  吴建梅祁建民 周瑞阳 《中国麻业》2004,26(6):261-266

采用双列杂交遗传设计和加性-显性遗传模型，分析了7个红麻杂交亲本和21个F1组合的11个产量与品质性状，结果表明：(1)株高、鲜皮厚、千粒重、纤维支数同时受到加性和显性效应的控制；而茎粗、单株干皮重、单株干茎重、皮骨比、出麻率、单株纤维重、精洗率、纤维强力主要受显性效应控制。(2)对红麻亲本遗传效应估测结果表明，各亲本不同性状的遗传效应不同。可根据亲本对每个性状的不同遗传效应表现，在育种和杂种优势利用上加以选择利用。综合分析表明，福红2号、福红992和非洲裂叶3个亲本具有提高株高、茎粗、鲜皮厚、单株干皮重、单株干茎重、出麻率、皮骨比、精洗率、单株纤维重的正向遗传效应：福红2号和福红9922个亲本还具有提高纤维强力与纤维支数的遗传效应。上述结果可为红麻遗传改良和杂种优势利用提供一定的科学依据。  相似文献   

Elevated atmospheric CO2 effects on N fertilization in grain sorghum and soybean     

《Field Crops Research》2004,88(1):57-67

Increasing atmospheric CO₂ concentration has led to concerns about global changes to the environment. One area of global change that has not been fully addressed is the effect of elevated atmospheric CO₂ on agriculture production inputs. Elevated CO₂ concentration alterations of plant growth and C:N ratios may modify C and N cycling in soil and N fertility. This study was conducted to examine the effects of legume, soybean (Glycine max (L.) Merr.), and non-legume, grain sorghum (Sorghum bicolor (L.) Moench.) carbon dioxide-enriched agro-ecosystems on N soil fertility in a Blanton loamy sand (loamy siliceous, thermic, Grossarenic Paleudults). The study was a split-plot design replicated three times with crop species (soybean and grain sorghum) as the main plots and CO₂ concentration (ambient and twice ambient) as subplots using open top field chambers. Fertilizer application was made with ${}^{15}\text{N}$-depleted NH₄NO₃ to act as a fertilizer tracer. Elevated CO₂ increased total biomass production in all 3 years of both grain sorghum (average 30%) and soybean (average 40%). With soybean, while no impact on the plant C:N ratio was observed, the total N content was greatly increased (average 29%) due to increased atmospheric N₂ fixation with elevated CO₂ concentration. With grain sorghum, the total N uptake was not affected, but the C:N ratio was markedly increased (average 31%) by elevated CO₂. No impact of elevated CO₂ level was observed for fertilizer N in grain sorghum. The results from this study indicated that while elevated CO₂ may enhance crop production and change N status in plant tissue, changes to soil N fertilizer application practices may not be needed.  相似文献   

Genotypic variation in patterns of root distribution, nitrate interception and response to moisture stress of a perennial ryegrass (Lolium perenne L.) mapping population   总被引：1，自引：0，他引：1  

J. R. Crush  H. S. Easton†  J. E. Waller  D. E. Hume†  M. J. Faville† 《Grass and Forage Science》2007,62(3):265-273

Genotypic variation in patterns of root distribution, nitrate interception and response to moisture stress were assessed in both parents and 198 progeny of a perennial ryegrass (Lolium perenne L.) full‐sibling mapping population. This was carried out in metre‐deep tubes of sand culture in a glasshouse experiment. The proportion of root dry matter (DM) weight in the top 10 cm of sand ranged from 0·33 to 0·75 and values of log₁₀(1 ? K), where K is the constant for an exponential model relating root DM weight and root depth, also showed wide variation among genotypes. The proportion of a pulse of ¹⁵N recovered in whole plants ranged from 0·124 to 0·431. There was a positive linear correlation between the proportion of ¹⁵N recovered and plant total DM weight, but no relationship between nitrate interception and patterns of distribution of DM weight of roots. Some genotypes responded to moisture stress by increasing root growth, and in others root growth was inhibited. It is concluded that this below‐ground variability in root variables may be an evolutionary adaptation by plant populations to survive heterogeneity in soil biotic and edaphic factors.  相似文献   

New approaches concerning the utilization of natural amendments in cadmium phytoremediation     

Alina Stingu  Valentin I. Popa 《Industrial Crops and Products》2012,35(1):53-60

Different vegetal biomass resources such as Picea abies bark, Castanea sativa chestnuts shell and Asclepias syriaca plant were considered to provide a source of natural bioactive compounds, which can be properly used in several directions such as: plant growth regulators and amendments in bioremediation. Having in mind a complex processing biomass technology, these raw materials are used in a first step to separate bioactive compounds by an aqueous extraction. The obtained extracts containing polyphenols were tested in germination tests to evaluate their influence on cadmium bioaccumulation in oat plant (Avena sativa). It was observed that the mentioned extracts modulated cadmium bioaccumulation, photosynthesizing pigments biosynthesis, plant growth and its development depending on metal ion concentration (5, 12.5, 25 mg/L), and extracts composition determined by vegetal raw material and their total polyphenols content (130, 122, 114 mg/L related to gallic acid). FTIR spectra and histo-anatomical cross section of the roots certify that P. abies bark and A. syriaca plant extracts amendments stimulated cadmium bioaccumulation, promoting the translocation of heavy metals to the aerial part of the plant, meanwhile chestnuts shell extract reduced the mobility of cadmium determining in situ inactivation of heavy metal ions.  相似文献   

Enhanced kernel set promoted by synchronous pollination determines a tradeoff between kernel number and kernel weight in temperate maize hybrids     

Martín Uribelarrea  Jorgelina Cárcova  Lucas Borrás  María E. Otegui 《Field Crops Research》2008

Maize (Zea mays L.) grain yield is strongly related to the number of harvested kernels, where kernel number can be increased by synchronously pollinating silks rather than allowing them to be progressively pollinated as they naturally appear from the husks. However, there is scarce evidence on how this practice affects kernel weight (KW) and plant grain yield (PGY), and no report exists on its effects when combined with treatments aimed to reduce apical dominance, like male sterility and detasseling. Field experiments were conducted in two growing seasons (Exp₁ and Exp₂) using two hybrids, cropped at contrasting stand densities (3 and 9 plants per m²) and including (i) male-fertile and male-sterile versions, (ii) tasseled and detasseled plants, and (iii) natural (NP) and synchronous pollination (SP; pollen added manually to ears bagged 5 days after initial silking) systems. Tassel growth of sterile and fertile versions was also evaluated in a separate experiment (Exp₃). Detasseling increased the number of ears per plant reaching silking (P < 0.001) of NP plants, but this beneficial effect of reduced apical dominance did not improve kernel number per plant (KNP) or PGY. Similarly, the early arrest of anther growth in male-sterile plants had no clear benefit on KNP. In contrast, KNP was enhanced by synchronous pollination (range between −13% and +71%; average of +15.4% in Exp₁ and +3.9% in Exp₂). However, this pollination system promoted a decreased in KW (range between −30% and +4%; average of −11.8% in Exp₁ and −7.8 in Exp₂) such that the treatment had no effect on PGY (range between −19% and +37%; average of +1% in Exp₁ and −4% in Exp₂). Because plant growth rate around flowering was not different between pollination treatments, assimilate availability per kernel was reduced from ovary fertilization onwards in synchronously pollinated plants when compared to open pollinated plants. This explains the reduced KW when increasing KNP by synchronous pollination. In summary, none of the imposed treatments allowed grain yield to be increased at the plant level.  相似文献   

Changes of soluble protein expression and leaf metabolite levels in Arabidopsis thaliana grown in elevated atmospheric carbon dioxide     

《Field Crops Research》2004,90(1):61-73

Plant responses to elevated atmospheric CO₂ vary with species and with environmental conditions. Rates of dry matter formation were initially enhanced in response to CO₂ enrichment but these accelerated growth rates typically were not maintained over long periods of time. The objective of this study was to better understand the basis for this acclimation process. Changes of metabolite levels and of total protein expression in response to CO₂ enrichment were studied using biochemical assays and two-dimensional gel electrophoresis. Arabidopsis thaliana (L.) Henyh. (Columbia ecotype) plants were grown for 2–6 weeks in controlled environment chambers providing 36 (ambient) or 100 (elevated) Pa CO₂. Averaged over all harvest dates above-ground biomass was greater (P < 0.05) in the elevated than in the ambient CO₂ treatment but shoot biomass did not differ between treatments on the final harvest. Flowering was delayed by CO₂ enrichment. One or more flowers were observed for 52% and 100% of the elevated and ambient CO₂ grown plants, respectively, after 4-weeks growth. Starch and sucrose levels were increased 132 and 43%, respectively, in leaves of 6-week-old plants in response to CO₂ enrichment. Nitrate varied with plant age, although mean nitrate levels in rosettes were decreased 31% by CO₂ enrichment when averaged over all harvest dates. Chlorophyll, the chlorophyll a/b ratio, carotenoids and total soluble protein did not differ between CO₂ treatments. Total Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity decreased with plant age and was lower (P < 0.01) in the elevated compared to the ambient CO₂ treatment. The above results suggested that acclimation to elevated CO₂ occurred in Arabidopsis without developing symptoms of N-deficiency. A total of 400 major proteins were separated and compared by two-dimensional gel electrophoresis. No proteins appeared de novo or disappeared in response to CO₂ enrichment, although pixel densities for 13 protein spots differed significantly between CO₂ treatments on at least one harvest date. Six of these proteins were identified by mass spectrometry. Three of these identified proteins were involved in plant growth and development or were associated with stress. Two other proteins were encoded by genes with putative functions. Only one protein, the 23 kDa subunit of the oxygen evolving complex (OEC23), was involved in photosynthesis. It was concluded that long-term plant growth in elevated CO₂ caused only small changes in the Arabidopsis proteome.  相似文献   

黑龙江红麻引种品比试验简报     

魏国江  潘冬梅  刘淑霞  刘玉  韩喜财 《中国麻作》2014,(1):13-16

2011年在黑龙江省大庆市对7个品种（品系）开展南种北引的品比试验,红麻株高生长曲线呈单S型,表现为前期一个月处于生长缓慢时期,生长速度为0.89 cm/日;中期一个半月进入快速生长期,生长速度为3.92 cm/日;后期一个月处于缓慢生长期,生长速度为1.10 cm/日。品比试验表明H1表现突出,株高为265.7 cm,茎粗为1.56 cm,叶数40个,干麻皮厚为1.42mm,出皮率为43.1％,干茎25.51t/hm2,比福红2号（对照）增产39.3％,其麻皮成熟度好,抗病性、抗倒伏性、抗盐碱性强。  相似文献   

Root-knot and reniform nematode reproduction on kenaf and sunn hemp compared with that on nematode resistant and susceptible cotton     

《Industrial Crops and Products》2001,13(3):249-264

Kenaf (Hibiscus cannabinus L.) and sunn hemp (Crotalaria juncea L.) are industrial fiber crops that are being grown increasingly in areas where cotton (Gossypium hirsutum L.) is the major crop. The nematodes causing most cotton yield losses in the USA are the southern root-knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood, and the reniform nematode, Rotylenchulus reniformis Linford and Oliveira. For nematode management, knowledge about the comparative effects of kenaf, sunn hemp, and cotton on nematode population densities in the soil is important. The objective of this study was to clarify the host status of kenaf and sunn hemp to M. incognita and R. reniformis by directly comparing reproduction of each nematode on each crop with the same nematode's reproduction on nematode-resistant and nematode-susceptible cotton. Comparisons were made in six experiments under growth chamber, microplot, and field conditions. The results showed that sunn hemp is resistant, but not equally resistant to M. incognita and R. reniformis. Reproduction of R. reniformis on sunn hemp was nearly undetectable, whereas reproduction of M. incognita was greater than on resistant cotton (Auburn 623, Auburn 634) and up to 20% of that on susceptible cotton (Deltapine 16, Deltapine 50, or Deltapine 5409). Kenaf was confirmed to elevate populations of M. incognita to levels that devestate cotton, but found to support substantially less reproduction by R. reniformis than cotton does. Two populations of R. reniformis differed substantially in reproduction on kenaf even though the same populations reproduced similarly on cotton. In conclusion, distinguishing M. incognita from R. reniformis is essential to the management of nematodes in rotations involving kenaf, sunn hemp and cotton.  相似文献   

Temporal variation in nitrogen concentration of above ground perennial ryegrass applied different nitrogen fertiliser rates     

《Field Crops Research》2005,91(1):83-90

Perennial ryegrass (Lolium perenne L.) was grown for seed in field trials in order to investigate the temporal variation in plant nitrogen (N) concentration during ontogeny. Crops were sown in three successive years and grown with five N fertiliser rates applied in the autumn and in the spring (autumn–spring): 0–0, 0–50, 0–100, 30–120 or 60–140 kg N ha⁻¹. Within each N fertiliser rate, N concentration in the plants increased from the initiation of spring growth and reached a maximum of 4.8% at 450–500 growing degree-days (GDD) after which it decreased to 0.8% at 1150–1200 GDD. This pattern of plant N concentration was consistently low at each N fertiliser rate and between years whereas the variation in plant N concentration within each year was high as a result of the different N fertiliser rates. Nitrogen fertiliser rate up to 150 kg N ha⁻¹ increased the seed yields.During spring growth 89% of the variation in plant N concentration could be explained by a non-linear function of GDD. Maximum variation occurred at 480 GDD, with a 95% confidence interval between 428 GDD and 540 GDD. Plant N concentrations measured at 424 GDD in 1998, 447 GDD in 1997, and 497 GDD in 1996, and the resulting correlation coefficients (r²) between N concentration and seed yield were 0.81, 0.71 and 0.92, respectively.It is concluded that the variation in plant N concentration during ontogeny in perennial ryegrass is related to different N fertiliser rates and that the greatest variation in plant N concentration was in the period from 428 GDD to 540 GDD.  相似文献   

Influence of the growth stage of industrial hemp on chemical and physical properties of the fibres     

《Industrial Crops and Products》2001,13(1):35-48

Fibre damages by the decortication process have to be avoided to achieve high quality of hemp fibres (Cannabis sativa L.) for industrial use. In addition, a well-defined separation of the single fibres by the subsequent degumming process is required. The objective of the present study is to determine the growth stage at which bark and shives can be separated from unretted industrial hemp (variety ‘Kompolti’) with as little fibre damage as possible. Furthermore, the chemical composition of the bark and the molecular weight of fibre cellulose have been analysed to estimate the fibre quality that can be achieved after a degumming process. For this, the fibres have been extracted by a standardised chemical degumming process. The investigations were carried out at nine growth stages of the plants reaching from vegetative stages to senescence. Considering only the mechanical decortication of green dry stems without degumming of the bark, the results reveal that a harvest time at the beginning of seed maturity leads to easier decortication without any effect on the tensile strength of the bast. For decortication of fresh stems including a subsequent degumming process, a harvest after the flowering of the male plants results in fibre losses during decortication and to fibres of reduced fineness.  相似文献   

Different plant parts as raw material for fuel and pulp production     

《Industrial Crops and Products》2000,11(2-3):119-128

Reed canary grass (Phalaris arundinacea L.), meadow fescue (Festuca pratensis Hudson), tall fescue (Festuca arundinacea Schreber) and goat’s rue (Galega orientalis L.) were harvested at seed ripening stage and in the following spring when the plants were totally dry. The amounts of different plant parts (grasses: stem, leaf sheaths, leaf blades and panicles; goat’s rue: stem, leaf blades and pods) were measured and the composition of ash, silica (SiO₂), iron (Fe), manganese (Mn), copper (Cu) and potassium (K) was analysed for each plant fraction. Plant species, plant part and harvesting time affected the mineral composition; grasses contained more SiO₂ and K, but less Cu than goat’s rue. The mineral concentrations were highest in leaf blades. In each species, stem fractions had the lowest ash, SiO₂, K, Fe, and Mn contents. The proportion of stem was highest in reed canary grass and goat’s rue when harvested in spring. The K concentration was clearly lower in plants harvested in spring than at seed ripening stage in autumn. However, the concentrations of SiO₂, Fe, Cu and Mn were highest at spring harvesting. Spring harvest of reed canary grass yielded clearly higher fibre contents for each plant fraction than harvesting in autumn. Of the species studied, reed canary grass suits best for raw material, if the leaf blades are removed and harvesting is done in spring at senescence stage of plants.  相似文献   

Fatty acid and oil variation in seed from kenaf (Hibiscus cannabinus L.)     

R. Coetzee  M.T. Labuschagne  A. Hugo 《Industrial Crops and Products》2008,27(1):104-109

Kenaf (Hibiscus cannabinus L.) is a fibre plant native to east-central Africa. The potential for using kenaf seeds as a source of edible oil is often overlooked when considering kenaf as a fibre and feed crop. The aim of this research was to study and compare the fatty acid composition and oil content of eight commercial kenaf varieties from various countries. Linoleic, oleic, and palmitic acid were the predominant fatty acids in all cultivars. Percentages of fatty acids varied greatly among different kenaf varieties. Gregg had the highest percentage of linoleic acid whilst El Salvador had the lowest. El Salvador had the highest percentage of oleic acid and Endora had the highest percentage of palmitic acid. Stearic acid and palmitic acid were positively correlated, as well as stearic and linoleic acid. Increasing stearic and linolenic acid and reducing palmitic acid at the same time therefore might be difficult through conventional breeding. The oil content was 19.84% on average and there was not much difference between the varieties. The relatively high oil content and the unique fatty acid composition, suggested that kenaf seed could be used as a source of edible oil. Kenaf oil can be considered nutritionally healthy because of the relatively high amount of monounsaturated and polyunsaturated fatty acids.  相似文献   

Elongation rate of sorghum leaves has a common response to meristem temperature in diverse African and European environmental conditions     

《Field Crops Research》1998,58(1):69-79

We have tested whether thermal time can account for the effect of meristem temperature on leaf appearance rate (LAR) and leaf elongation rate (LER) of sorghum in a wide range of conditions without water or nutrient deficits. This requires that responses to temperature should be consistent in different locations and different seasons, and that responses of LER of different leaves of the plant should be similar. Sorghum plants (Sorghum bicolor (L.) Moench., cv. E-35-1) were sown in the field in Bamako (Mali) from October 1995 to August 1996, in Montpellier (France) in summers 1995 and 1997, and in a growth chamber. Irradiance, air and meristem temperatures (T_m) and air humidity were measured together with LER in all experiments. Unique and tight relationships were observed between T_m and LER of leaves located at different positions on the stem, for all experimental conditions when evaporative demand was low (meristem-to-air vapor pressure deficit, VPD_ma, lower than 2.5 kPa). Relationships remained linear over the whole studied range of T_m, i.e. 13–32°C (R², from 0.7 to 0.87). With high evaporative demand, LER was lower than the LER expected at the same temperature but with low VPD_ma (LER_reg); the normalized difference between LER measured on a given day (LER_a) and LER_reg was linearly related to VPD_ma (R²=0.52). A linear relationship was also observed between T_m and LAR measured before the beginning of stem elongation when T_m was lower than 27°C. The x-intercepts of relationships between T_m and LER or LAR did not differ in a covariance analysis, with a common value of 10.8°C. The use of thermal time without corrections for high temperature or photoperiod was the most appropriate way to account for the timing of leaf development. It allowed prediction of LER provided that the reduction in LER due to evaporative demand was taken into account.  相似文献   

Effects of pasture age on the genotype and phenotype of perennial ryegrass     

Marty J. Faville  James R. Crush  Won Hong  Holly Phillips  Julia M. Lee  David Chapman 《Grass and Forage Science》2020,75(2):135-144

Limited persistence of perennial ryegrass (Lolium perenne L.) in dairy pastures is a significant issue in parts of New Zealand. The contribution of plant genetic background to this problem is not well understood. Temporal changes were investigated in genotypic and phenotypic composition of two perennial ryegrass cultivars (Nui SE and Alto AR37, older and newer cultivars respectively) sown as fields plots at three locations. Samples from survivor populations collected annually over 6 years from each location were established in a field nursery, analysed by simple sequence repeat (SSR) markers and assessed for vigour, leaf morphology and tiller number. SSR-based estimates of the statistic G′_ST indicated no significant (p > .05) genetic differentiation between survivor populations and plants grown from remnant seed (ex-seed) after 5 years, and no significant change (p > .05) in within-population genetic diversity for either cultivar at any location. SSR analysis of endophytic fungus (Epichloë festucae var. lolii) type revealed only limited ingress of off-type ryegrass volunteers into plots at two locations. Vigour scores of survivor plants were not significantly (p > .05) different among plants collected from different locations and ex-seed plants. Leaves on ex-seed plants were longer (p < .001) than those on the survivor plants after four but not 6 years and may reflect a short-term response to climatic conditions experienced in the field nursery. Our results suggest that the reported poor ryegrass persistence is not driven by changes in population genetic structure and that the sown cultivars survived and remained true to type.  相似文献